Development of a new method and a device for mechanical imaging of breast tissue and visualizing internal structures in terms of elasticity modulus is proposed. This device will be capable of detecting breast nodules and can be used for breast cancer screening. The method realized in the device, the Mechanical Imaging (MI), is safe and does not use any form of hazardous radiation. It uses the same mechanical information as obtained by manual palpation to determine presence of nodules in the breast, but objectively and with higher sensitivity and accuracy. Results of the initial clinical, physical and mathematical pilot studies as well as of Phase I of this project indicate that the proposed method can, in principle, meet many of the requirements of an ideal screening method: it has a potential of detecting breast cancer in an early nonpalpable stage, it is non-invasive, safe, easy-to-use, and inexpensive. Clinical validation of the device and establishing protocols for breast examination of patients with suspected breast cancer and other breast complaints will be conducted at the Department of Radiology of the University of Michigan in Ann Arbor. Mammography, the current method of breast cancer diagnosis and mass screening, has a number of drawbacks, such as use of hazardous x-rays, significant percent of false negative diagnosis even for palpable tumors, high costs of the equipment, high levels of static pressure over the breast needed to achieve good quality image, it requires special personnel to service the device and radiologists to read images. The MI method is free of some of these drawbacks and can be used at much wider scale and more frequently than mammography. MI cannot replace mammography because these two techniques overlap only to a limited extent and they are sensitive to tissue features greatly differing in their physical nature. MI complements mammography by providing safe and accessible means of mass pre-screening of wider population in a technically less sophisticated medical care institutions. PROPOSED COMMERCIAL APPLICATION: The convenience, affordability, and non-invasive nature of this technology will provide the basis for the development of new markets for a product, that should be a necessary item in any general healthcare institution. Delivering the potential of this non-invasive diagnostic tool to wider fraction of population and its more frequent use than mammography could result in a significant decrease of the size of breast cancers at detection and consequently, more effective treatment, decrease in patient morbidity and mortality, and reduced health care costs.